Abstract
The effect of pressure(up to 20 bar)on the reactivity of a char(150–160 μm) produced from Western Australian Collie coal has been studied using a high-pressure thermogravimetric analyser (HP TGA). The pressure demonstrated a positive effect in enhancing char combustion reactivities.Kinetic parameters have been determined from the experimental data.The apparent reaction order was found to be approximately 0.7 and the apparent activation energies were 91.0 kJ/mol at atmospheric pressure and 1.5 kJ/mol at an elevated pressure(10 bar),indicating a shift in the control regimes of the reaction at elevated pressures.The lumped effect of the sample size, bulk diffusion,interparticle and intraparticle diffusion at the elevated pressures played an important role in reducing the mass transfer during the HP-TGA experimentation.Thus the activation energy calculated at elevated pressures may not represent the intrinsic activation energy of the char particles but the apparent values of the bulk of the samples.
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Abbreviations
- A::
-
Apparent pre-exponential factor, g/g/s/barn
- A.C.:
-
Ash content
- Ea::
-
Apparent activation energy, kJ/mol
- F.C.:
-
Fixed carbon
- k::
-
Apparent rate constant, g/g/s/barn
- n::
-
Apparent reaction order
- PO2::
-
Partial pressure of oxygen, bar
- R::
-
Universal gas constant, J/mol·K
- \( \dot{r} \)::
-
Apparent reaction rate, g/g/s
- T::
-
Temperature, K
- t::
-
Time, s
- V.M.:
-
Volatile matter
- W::
-
Carbon remaining in the char sample, g
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© 2013 Springer-Verlag Berlin Heidelberg & Tsinghua University Press
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Chan, Y.L., Zhang, Z., Zhu, M., Luan, C., You, C., Zhang, D. (2013). A Preliminary High-Pressure Thermogravimetric Study of Combustion Reactivity of a Collie Coal Char. In: Qi, H., Zhao, B. (eds) Cleaner Combustion and Sustainable World. ISCC 2011. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-30445-3_19
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DOI: https://doi.org/10.1007/978-3-642-30445-3_19
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